Shielded printed circuit card holder

ABSTRACT

This invention is directed to a fully shielded printed circuit (PC) card holder, that may be readily &#34;snapped&#34; into the assembly, or disassembled, as the case may be. The holder is intended to receive a PC card, where at least one end of the card is adapted to be electrically connected to an I/O type connector. The holder comprises a generally rectangular bottom cover member formed of a conductive material, corner supports integrally molded to the bottom cover member at the respective corners thereof, where each support includes a lower flange portion to which the bottom cover member is exposed. Further, a generally rectangular upper cover member is provided where the periphery thereof includes a downwardly extending flange adapted to engage the lower flange portion in electrical contact with the bottom cover member over a substantial portion of the periphery thereof. In the assembled condition, the holder provides continuous shielding against distortion of data signals between the PC card and the I/O type connector.

RELATED APPLICATION

This invention represents an improvement to the memory card shieldingapparatus disclosed and claimed in U.S. Ser. No. 07/996,560, filed Dec.24, 1992, assigned to the assignee hereof.

BACKGROUND OF THE INVENTION

With the advent of sophisticated computers, facsimile machines,printers, and other computer-related electronics equipment, the need forexternal printed circuit (PC) interface to be used by the computer andcomputer-related equipment is ever increasing. To this end, PC cardscontaining external memory and data to be used in computer processeshave been designed. At the present time, there are three different PCcard types, as defined by the Personal Computer Memory CardInternational Association (PCMCIA). This is the standards bodyresponsible for developing the 68-pin PC card standard. The three PCcard types, are as follows:

a. Type I PC Cards are the same width and length as a common creditcard, 54 mm×85.6 mm, but are thicker than a credit card. The thicknessof a Type I card is 3.3 mm (0.130").

b. Type II PC Cards are used by those companies which are utilizingmemory components that are too high to be housed within a Type I card.Type II memory cards are also the same overall length and width ascredit cards, but have raised body cross section in the substrate areawhich gives them an overall thickness of 5 mm (0.195"). The raisedsubstrate areas of these cards are 48 mm in width.

c. Type III PC Cards are the result of a recent movement sponsored bythe Small Form Factor Committee (SFF) to enable 1.8" Small Form FactorDisk Drives to be plugged into memory card connectors in small portablecomputer applications. Type III PC cards are the same length and widthas Type I and Type II PC cards. However, Type III cards have a substratearea thickness of 10.5 mm. Also, Type III PC cards require a card guideopening width of 51 mm of the header connector to accommodate theslightly raised substrate area.

PC cards generally comprise a printed circuit board, a casing made of aninsulting material for housing the printed circuit board, and at leastone connector, typically referred to as an "I/O" connector. Theconnector is provided on one end of the casing for interfacing thememory card, and particularly the printed circuit board contained in thecasing, to the computer equipment to which the card is mated. Theconnector is designed to extract the contents of the memory stored onthe printed circuit board and to bus data to and from an outsideenvironment, which also usually comprises a computer or other electronicequipment. In this fashion, data traverses the interface between the PCcard and the outside environment so that the data can be efficientlytransferred and used by the computer to which the card is mated for itsintended purpose.

PC cards are generally interchangeable and can be used with manydifferent machines and electronic components. Because the PC cards areinterchangeable, they undergo a significant amount of abuse whentransported, interfaced and mated to the different computers andelectronic equipment which use them. Since a PC card is conventionallymade up of a number of layers and/or elements glued or otherwise bondedtogether, the individual layers tend to become loose and/or separatedfrom one another as the memory card is subject to flexing stress, astypically occurs when the card is inserted into or removed from theelectronic or other computer-type equipment. Thus, even after moderateamounts of usage, conventional memory cards have heretofore frequentlybecome structurally loose, and the internal members of the card oftenbecome misaligned. This results in failure of the PC card and degradesthe performance of the electronic equipment which uses the card. Theseundesirable results generally induce poor performance of the computersystem which uses the memory card.

Another undesirable result which induces poor performance of thecomputer system results from inadequate shielding of the PC card and theconnectors electrically connected thereto. In the prior art, PC cardshad separate shields which were provided proximate the variouscomponents of the card. This discontinuous shielding provided breaks inthe shielding and limited the effectiveness of the memory card,particularly in environments in which many electronic devices werelocated. Notwithstanding the above, U.S. Pat. No. 5,005,106 teaches asystem for providing continuous shielding to a substrate. Specifically,the patent teaches the use of a flexible, conductive envelope into whichthe substrate may be inserted, then placed within an insulative housing.

The present invention avoids these undesirable results or complexitiesby the provision of a continuous shielding arrangement that is easy toassemble. The uniqueness of this arrangement will become apparent fromthe description which follows, particularly when read in conjunctionwith the accompanying drawings.

SUMMARY OF THE INVENTION

This invention is directed to a shielded PC card holder, particularlyfor Type I and Type II cards, where such holder offers continuousshielding thereto, by the combination of a bottom cover integrallymolded to the card frame and a cover men, her that will snap fit ontosaid bottom cover/frame. The holder comprises a generally rectangularbottom cover formed of a conductive material, and corner supportsintegrally molded to the bottom cover at the respective corners thereof,where each said support includes a lower flange portion to which thebottom cover is exposed. Matable therewith is a generally rectangularupper cover whose periphery includes a downwardly extending flangeadapted to engage the lower flange portion in electrical contact withthe bottom cover over a substantial portion of the periphery thereof,whereby to provide continuous shielding against distortion of datasignals between the PC card and an I/O type connector.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view of an assembled, fully shielded PC cardholder according to this invention.

FIG. 2 is an exploded, perspective view, including a PC card forcontainment therein, of the memory card holder of FIG. 1.

FIG. 3 is a sectional view taken along line 3--3 of FIG. 2.

FIG. 4 is an enlarged, partial, sectional view of the PC card holder ofFIG. 2, taken of a longitudinal section.

FIG. 5 is an enlarged, partial, sectional view of the PC card holder ofFIG. 4, in an assembled and shielded position.

FIG. 6 is an enlarged, partial, sectional view taken through theintegral grounding clip, forming part of the upper cover member.

FIG. 7 is an enlarged, partial, sectional view of the PC card holder ofFIG. 6, in an assembled and shielded position, taken along line 7--7 ofFIG. 1.

FIG. 8 is an enlarged, partial, sectional view taken along line 8--8 ofFIG. 1.

FIG. 9 is a view similar to FIG. 8 illustrating the manner by which thePC card holder of this invention may be disassembled.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT

Referring now to the several figures representing the preferredembodiment of this invention, FIGS. 1 and 2 illustrate an assembled andexploded views respectively, of the PC card holder 10 comprising abottom cover member 12 of a conductive material, such as metal,integrally molded with a dielectric frame 14, and an upper cover member16, stamped and formed of a conductive material, such as metal, wheresuch cover members 12, 16 are adapted to receive and provide shieldingto a PC card 20 therebetween.

A typical PC card may consist of a printed circuit board (PCB), as knownin the art, or other type of planar circuit element adapted to store,receive and/or transmit data. Additionally, the PC card 20 may beprovided with at least one connector as known in the art, where areceiving cavity therefore is designated by the numeral 22, so that theconnector may mechanically and electrically interface with the PC card20.

The PC card 20 preferably requires a second connector, not shown, suchas along the opposite edge 25 28, for mating the PC card to a computeror other device (not shown) which will utilize the card's memory and/orperform computer operations on data which is stored in the PC cardand/or received from the outside environment through the connector incavity 22. In general, the computer or second connector is of atwo-piece construction having a posted header for loading onto the hostequipment, such as a computer, and a receptacle assembly which is usedby the PC card 20, as known in the art.

Returning now to the holder 10, specifically the integrally moldedbottom cover 12 and frame 14, the frame thereof includes a pair of siderails 30 having exposed longitudinal surface portions 32 for receivingand supporting the contained PC card 20. Additionally, the frame 14 mayinclude at least one transverse member 34 to provide structuralintegrity to the frame and support for the PC card.

As best seen in the sectional views of FIGS. 3-5, the bottom covermember 12 is essentially a planar member disposed outside the frame 14,except at the edges 36 thereof. The bottom cover member 12 is formed atsuch edge 36 to yield a peripheral shoulder portion 38 and an upturnededge 40 which is integrally molded into the frame 14, thereby fixing therelative position of the bottom cover member 12 to said frame 14.

Along the side rails 30, plural spaced-apart recesses 42 have beenprovided. As will be explained hereinafter, in connection with FIGS. 8and 9, such recesses 42 facilitate the receipt of a suitable tool toallow for the easy removal of the cover member 16 for replacement of thePC card 20. Additionally, a further single recess 44 is included alongone of said side rails 30 to accommodate an inturned grounding tab 46,the design and function of which is best illustrated in FIGS. 6 and 7.

Returning now to the upper cover member 16, which is intended to be`snap` fitted onto the frame 14 in electrical contact with bottom cover12, the major or longitudinal sides 50 are characterized by essentiallycontinuous inturned flanges 52. The transverse edges 54 arediscontinuous to the extent that each may accommodate a connector forengagement with the PC card 20, typically along a midpoint thereof.However, at least at the ends 56 thereof, such ends 56 further includeinwardly directed flanges 58 for engagement with the frame 14.

To facilitate the assembly of the PC card holder 10, after placing a PCcard 20 therein along surface portions 32, it will be noted that siderails 30 have tapered conforms 60, see FIGS. 4-7, such that as the uppercover flanges 52, 58 contact the tapered surface 60 and the flanges flexoutward until they reach the lower most edge 62, then resile intocontact 64 with the exposed shoulder portion 38. FIG. 5 best illustratesthe latching arrangement of the holder assembly, where it will be seenthat the flanges 52, 58 of the upper cover are spaced from the taperedor camming edge 60 and remain in a slightly flexed position so as toinsure a constant gripping force and electrical engagement between therespective cover members.

As noted previously, the upper cover member 16, stamped and formed froma sheet metal blank, is provided with a grounding tab 46 or strapaligned with the recess 44. The end 70 of the tab 46 includes a flatportion which is adapted to engage grounding traces, as known in the arton the surface 72 of PC card 20, thereby assuring suitable groundingthereof.

FIGS. 8 and 9 demonstrate the manner by which the cover members 12, 16may be readily separated, as desired. The side rails 30 of the frame 14have been provided with the plural recesses 42. When disassembly of theholder 10 is required, a suitable bladed tool, where the base 80 isshown in FIGS. 8 and 9, may be inserted at the contact edge 62, betweenthe cover members 12, 16 into the recesses 42. With this action, theflanges 52, 58 are flexed outwardly and freed of the outermost edge 62for easy removal. A preferred tool for such assembly, though notillustrated in the several figures, can be a planar member, coextensivein dimension to the bottom cover member 16, having plural blade likelances projecting therefrom so that such action is uniformly appliedabout the periphery of the holder. Thus, by this construction, theholder 10 may be readily assembled, or disassembled, while providingeffective shielding during the use thereof.

We claim:
 1. A shielded printed circuit (PC) card holder for receiving a PC card, where at least one end of said card is adapted to be electrically connected to an I/O type connector, said holder comprising a rectangular bottom cover member formed of a conductive material, corner supports integrally molded to said bottom cover member at the respective corners thereof, where each said support includes a lower flange portion to which said bottom cover member is exposed, and a rectangular upper cover member whose periphery includes a downwardly extending flange adapted to engage said lower flange portion in electrical contact with said bottom cover member over a major portion of the periphery thereof, whereby to provide continuous shielding against distortion of data signals between the PC card and said I/O type connector.
 2. The shielded PC card holder according to claim 1, wherein said molded bottom cover member and said frame includes at least one transverse support member against which said PC card lies.
 3. The shielded PC card holder according to claim 1, wherein adjacent said corner supports are joined by rails, and said rail include a tapered edge to facilitate the assembly of said holder.
 4. The shielded PC card holder according to claim 3, wherein said rails include a plurality of recesses for receiving a disassembly tool.
 5. The shielded PC card holder according to claim 1, including a grounding tab internal with said upper cover member for electrically engaging corresponding grounding traces on said PC card.
 6. The shielded PC card holder according to claim 1, wherein said downwardly extending flange is in a flexed state when the holder is assembled, whereby to provide a constant contact force between said bottom and upper cover members. .Iadd.
 7. A shielded printed circuit (PC) card holder for receiving a PC card, where at least one end of said card is adapted to be electrically connected to an I/O type connector, said holder comprising an integrated lower cover and frame member, said lower cover comprising a metallic plate member having upturned portions adjacent to side edges thereof, said frame member comprising a pair of side rails molded on said lower cover member and encapsulating said upturned portions therein to secure said frame member to said lower cover, said card holder further comprising an upper cover securable to said integrated lower cover and frame member, for enclosing a PC card therein. .Iaddend..Iadd.8. The card holder of claim 7, wherein the upper cover comprises a metallic plate member shield. .Iaddend..Iadd.9. The card holder of claim 8, further comprising a PC card positioned therein which is grounded to one of said upper or lower covers. .Iaddend..Iadd.10. The card holder of claim 7, wherein the lower cover member comprises a peripheral shoulder portion. .Iaddend..Iadd.11. The card holder of claim 10, wherein said peripheral shoulder portion is raised relative to a plane defined by the metallic plate member of said lower cover member. .Iaddend..Iadd.12. The card hold holder of claim 11, wherein the upturned portions extend over the peripheral shoulder portions to facilitate molding of the upturned portions in the frame members. .Iaddend..Iadd.13. The card holder of claim 12, wherein the upturned portions are formed at the free edges of the lower cover, and are reversely bent inwards. .Iaddend..Iadd.14. The card holder of claim 10, 11, 12 or 13, wherein the side rails are molded over at least a portion of said shoulder portion, and the frame member conforms to said shoulder portion. .Iaddend..Iadd.15. The card holder of claim 7, wherein the upturned portions are formed at the free edges of the lower cover, and are reversely bent inwards. .Iaddend..Iadd.16. The card holder of claim 7, wherein said side rails further define a support surface for the printed circuit card. .Iaddend..Iadd.17. The card holder of claim 7, wherein said frame member comprises at least one transverse member integrally molded with said side rails and spanning between said side rails. .Iaddend..Iadd.18. The card holder of claim 7, wherein said side rails form an upper surface for contacting said upper cover. .Iaddend..Iadd.19. The card holder of claim 7, wherein said upper cover is fixed to said integrated lower cover and frame member. .Iaddend..Iadd.20. The card holder of claim 19, wherein said upper cover is removably fixed to said integrated lower cover and frame member. .Iaddend..Iadd.21. A printed circuit (PC) card holder, comprising a lower cover comprising a metal shell having upturned sections extending from said metal shell adjacent an outer periphery thereof, and an insulative frame member molded on said metal shell, said frame member encapsulating said upturned sections therein to secure said frame member to said metal shell; a printed circuit card within said lower cover; and an upper cover secured to said lower cover and enclosing said printed circuit card. .Iaddend..Iadd.22. The printed circuit (PC) card holder of claim 21, wherein the metal shell comprises a metal plate. .Iaddend..Iadd.23. The printed circuit (PC) card holder of claim 22, wherein the upper cover and lower cover are in grounding contact along a substantial portion of their respective outer peripheries. .Iaddend..Iadd.24. The printed circuit (PC) card holder of claim 21, wherein the upturned sections extend from outer edges of said metal shell. .Iaddend..Iadd.25. The printed circuit (PC) card holder of claim 21, wherein the upturned sections are turned inwardly so as to grip the frame member. .Iaddend..Iadd.26. A printed circuit (PC) card holder, comprising a frame member and a lower cover comprising a metal shell having at least one fixing section integrally molded in said frame member to secure said frame member to said metal shell; a printed circuit card peripherally within said lower cover; and an upper cover secured to said integrally molded frame and lower cover and enclosing said printed circuit card. .Iaddend..Iadd.27. The printed circuit (PC) card holder of claim 26, wherein the metal shell comprises a metal plate. .Iaddend..Iadd.28. The printed circuit (PC) card holder of claim 27, wherein the upper cover and lower cover are in grounding contact along a substantial portion of their respective outer peripheries. .Iaddend..Iadd.29. The printed circuit (PC) card holder of claim 26, wherein the at least one fixing section extends upwardly from an outer edge of said metal shell. .Iaddend..Iadd.30. The printed circuit (PC) card holder of claim 26, wherein the at least one fixing section is turned inwardly so as to grip the frame member. .Iaddend..Iadd.31. The printed circuit (PC) card holder of claim 26, wherein the frame member is molded of insulative material. .Iaddend..Iadd.32. The printed circuit (PC) card holder of claim 26, further comprising a connector mounted on said printed circuit card to provide an I/O interface. .Iaddend. 